Process and apparatus for mixing gases



Sept. 20, 1927. 1,643,065.

E. FALKENTHAL.

PROCESS AND APPARATUS FOR MIXING GASES Filed Dec. 18, 1924 Y Fig.1

Patented Sept. 20;

1,643,065 PA ENT, oF 1cE-..

nnwm iinnxnnrnat, or BERLLN-DLHLEIL GERMANY.

' rnocnss AND nrranarosro'n Mrxrns GASES.

Originalapplicationfiled October 4,1923 Serial No. 666,608, and in Germany April 23, 1921. Divideddand I I this application fileilDece'niberlS. m24. se1'-ia1:1qo.7*56,745.

This patent is a division of my application Serf N 0. 666,608 filed Oct. 4, 1923.

This invention relates to mixing process and apparatus for mixing gases, as for in- 5 stance ignition gases for combustion engines,

together. The object of the invention is a" mixing apparatus. offa novel kind foreffectuating afthor' ough mixing of gases, the latter being accomplished bya particular construction and "arrangement of one or moregrids placed in .a casing so as to divide the sameinto two orfmore compartments through which the unmixed and mixed gases are conducted Each grid is constructed so 16 as to produce'a peculiarefiect which consists. in its causing the gas passing through it to be divided up at the rear side of the grid into numerous whirls whereinthe mixing process takes place. To this end the 20 grid is formed .ofi'a thin sheet preferably of metal which has athickness about equal to drawing-paper thickness; namely 0.03 to 1.00 mm. and. provided with as manyregular openings as possible, which are equally 2 sized and have a smallest diameter of about tenfold the grids thickness, namely 0.30 to noted that the openings must in no way have the form of channels .whose length exceeds their diameter or of funnels whosediameter decreases towards their one end. The num'crous evenly distributed andsharp-edged 40 openings produce on the rear side of the grid numerous whirl-ringsi one for each opening, whereinthe gases are mixed with one another I and thoroughly intermingled, Without a noticeable throttling eflect. The distance apart from each other of the openrnust be suchthat there exists between ad] acentope'nings an unperforated area substantially equal with thearea of the adjacent openings According to fliisprinciple as a sample of dispositionin the case-of slitformed and parallel disposedopenings the solid-strip between eachitwo slits must he at least as broad as the width of aslit, the said strip andthe adjacent two half openingsproduce sharp edged meshes. It is to he forming in this case a so-called unit-area for disposing the openings on the grid-area.

"To ascertain whether the whirls are produced in the desired degree a sample of the grid intended'to be used is placed with its rear side near a flame. On the gas passing through the grid the flaring flame should show adistinctly defined whirling zone at the rear of the grid which merges verysud+ denly into a slowly moved gas zone;

For the purpose of the invention I have found, that advantageously the width of the openings is to be made as small as it is possible with respect to'the material of the grid sheet, and generally not greater than about 10 rnms. A greater speed of flow will generally require a smaller width of mesh.

The total area of the openings of one grid dependsupon the speed of the gas flowing through it and should be such that a throttling action or an obstruction of flow is avoided. By increasing the cross sectional area of the casing in comparison with the cross section of the inlet pipe by which the gas is conducted into the casing the sp'eed of flow at the grid can be reduced to any desired extent. It has been found in practice that in most cases the most favorable results are obtained at a speed of one meter per second. At this speed the diiference of pressure between the front and rear sides of the grid with slit-shaped openings 1 mm. in width and which occupy about 1/ of the grid s surface, corresponds to a pressure of a column of water 1*2 mm. high.

Theefliciency of a grid depends largely upon the number of whirl producing edges of the openings present in a unit of surface.

'paratus asin the known rebounding method by which the mixed gases are forcedto pass a relatively large row of reboundingperforated or channeled walls and for this reason each grid is that a large space is not required for theapthe new mixer according tozmyinvention is to be preferred wherever mixers of the ordinary kind would take up too much space.

In the case of gases which attack metal the grid is made from baltelite or similar artiticial substances which permit of sharp edged openings being made therein. The openings are produced by stumping, milling or drilling. I

The two gases to be mixed wlth one another are conducted one to the one side of the grid and the other to the other side of the grid, or two grids may be provided which form between them a mixing chamber, each oi? the two gases passing through one of the grids into the chamber between the grids. In the first mentioned case the lower pressed or the heavier gas is led immediately into the collecting chamber, the grid being passed only by the higher pressed or the more volatile gas.

The invention is illustrated in the drawing in which Fig. 1 shows a mixing chamber for mix ing two gases with two grids and Pi a fragment of a grid from the mixer of Fig. 1 in natural size.

The apparatus shown in Fig. 1 consists of a casing in the form of two lrustums of a hollow cone connected at their widest parts by a short cylinder, the narrow ends oi the frustums having inlet pipes at, b and the middle cylindrical portion being fitted with a pipe 0 for conducting oil the gas mixture. At both ends of the cylindrical portion grids G G are placed. The one gas is conducted in through the pipe (5 and the other through the pipe 5. The passage of the gases through the grids G causes them to term whirls in the cylindrical portion of the casing as indi atcd by the curved arrows and hereby an intimate mixing of the gases is brought about. The mixture is then drawn oil through the pipe 0.

Each grid G G is provided with vertical rows of slits as shown in Fig. 2. The imperiorate portion Z; between the slits is about equal in width to the length of a slit, so that the surface area oi a row of slits is about equal to the area of the impert'orate portion 7: between the rows. The land or unpcrtmrated strip may generally be made somewhat wider, say up to 1.5 the width of a row of slits.

It is thus seen that by an appropriate application of the invention apparatus must be constructed by which gases, may be pertectly mixed, in a simple and highly efficient. manner.

, I claim:

1. The art of mixing gases comprising passing at least one of the components of the mixture through a thin grid having small sharp edged openings the smallest diameter of which is substantially ten told the grid thickness and whose total area is substantially equal to the area of the imperiorate portions between the openings, maintaining the speed of the gas low relatively to the size of the openings in the grid to produce a whirling zone of gas immediately behind each grid opening, supplying the second gas to said grid at the rear thereof at a speed not greater than the speed of the first gas and discharging the gas mixture from behind the grid at substantially the induction speed.

2. The art of mixin gases comprising passing each gas through a thin grid into a chamber or which each grid forms a wall, each grid having small sharp edged openings, the smallest dimension of which openings is substantially ten told the grid thicle ness, the area of the openings being substan tially equal to the adjacent imperforate portions oi the grid, maintaining the speed of the gases low relatively to the size 01 the openings in the grid to produce a whirling zone of gas behind the grid at each opening in which the mixing of the gases takes place and discharging the gas mixture from the chamber at a speed of flow about equal to the induction speed.

Apparatus for mixin gases, comprising a vessel having gas inl et and gas outlet pipes, a plurality of thin grids spaced apart to form a mixing chamberand dividing the vessel into separate chambers said grids having a large number of regular openings, the openings having their smallest diameter about ten times the thickness of the grid and the distance apart of such openings being substantially equal to the imperforate adjacent portions of the grid, and each'opening having sharp edges, whereby a whirl ring is formed behind the grid at each opening by the sharp edge thereof when gases to be mixed are passed through said vessel at low speed and means to introduce the gases into said mixing chamber through each grid and in opposite directions.

l. Apparatus for mixing ing a vessel having gas inlet and gas outlet pipes, a pluralityot thin spaced grids in the vessel forming a mixing chamber, each grid having a large number of regular openings therethrough whose smallest diameter is about ten times the thickness of the grid and their distance apart substantially equal to their adjacent impertorate portions of substantially equal area and each opening having sharp edges that produce whirl rings in the gas behind the grids at each opening said gases introduced into the mixing chamber from opposite directions.

5. Apparatus for mixing gases, comprising a vessel having inlet and outlet pipes, a plurality of spaced grids inclosiug a mixing chamber in the vessel, means for supplying the gases to be mixed to said vessel and passing them through the grids to the chamgases, comprisber from opposite directions, each grid being thin and of about the thickness of drawing paper and having regular openings whose smallest diameter is about ten times the thickness of the grid, the distance apart of such openings being such that the imperferat-e portions of the grid adjacent the openings are about equal to the area of the openings and each opening has sharp edges that produce behind the grid adjacent each opening a whirl ring in the gas.

6. Apparatus for mixing gases, comprising a vessel, grids dividing the vessel into separate chambers and including between them a mixing compartment, means to supply gasto one chamber and another gas to another chamber for entrance into said compartment in opposite directions, said grid being of about the thickness'of drawing paper and having slit-shaped parallel openings whose width is about ten times the thickness of thegrid and arranged in rows, the space ing a vessel traversed by the gases to be mixed, spaced thin grids inclosing a mixing compartment dividing the vessel intochambers and having a thickness of about that of drawing paper, said grid having sharp-edged slit-like parallel openings arranged in rows, said openings having a width about ten times the thickness of the grid and spaced apart about'the same distance, the rows being separated by unperforated portions whose width is not less than V the width of a row and means to direct gases to said compartment through the grid from difierent directions. I

In testimony whereof I have signed my name to this specification.

ERWIN FALKENTHAL. 

